1. Field of the Invention
The present general inventive concept relates to a thin transformer used in a power source of an electronic apparatus, and specifically, to a thin transformer having a decreased thickness so that the thin transformer is used in a limited space of a product, such an electronic apparatus.
2. Description of the Related Art
Decrease in thickness and size of various types of electronic equipment has been required and developed. For example, liquid crystal display apparatuses, such as liquid crystal televisions or liquid crystal monitors, become a main stream of display apparatuses because the liquid crystal display apparatuses have a merit that it is possible to largely decrease a thickness of a product to efficiently use spaces, compared with conventional display apparatuses employing cathode ray tubes.
On the other hand, since transformers which are components necessary for power sources of the electronic equipment are increased in size in proportional to capacities of the power sources, it is different to decrease the electronic equipments in thickness and size. Specifically, considering a modern trend that external appearances should be made simple and beautiful by building the power sources within the liquid crystal televisions and the liquid crystal monitors, the thickness of the transformers is an important factor to decrease the thickness of products, such as the liquid crystal televisions and the liquid crystal monitors. For this reason, studies for decreasing a height of the transformers have proceeded, and a horizontal transformer has been employed. In the horizontal transformer, a coil bobbin around which a coil is wound is provided not vertically but horizontally with respect to a circuit board on which the transformer is mounted.
FIG. 1 is a perspective view illustrating a conventional horizontal transformer, and FIG. 2 is a front view illustrating the conventional horizontal transformer of FIG. 1.
In FIGS. 1 and 2, a coil 1 is wound around a coil bobbin 3 which is a hollow body having restriction projections 2 at both ends thereof, and terminal sections 4 formed integrally or separately with the restriction projections 2 are provided below the restriction projections 2. The terminal section 4 includes several terminals 5 perpendicular to a lower surface of the terminal section 4, drawn-out lines 6 of the coil 1 are connected to the terminals 5, and two “E” shaped iron cores 7 are inserted into the coil bobbin 3 to be disposed opposite to each other with respect to the coil bobbin 3. A protruding portion 8 is formed on an edge of the terminal section 4, where the protruding portion 8 serves as preventing connection portions between the drawn-out lines 6 and the terminals 5 from coming in direct contact with a circuit board during mounting the transformer on the circuit board. Actually, the circuit board is positioned below the transformer, and the terminals 5 are coupled electrically and mechanically to the circuit board through the terminals.
Since the coil bobbin 3 is provided not vertically but horizontally, a height of the transformer can be decreased. However, in this conventional horizontal transformer, the terminals 5 for electrical and mechanical connection to the circuit board are provided vertically to the lower surface of the terminal section 4, and in order to secure a mechanical strength, the terminal section 4 must have a thickness corresponding to a sufficient length of the terminals 5 to be buried thereinto. That is, the height of the transformer can not be decreased. Rather, the height of the transformer becomes increased. In addition, the height of the transformer is further increased due to the protruding portion 8 serving as securing spaces for connection between the drawn-out lines 6 of the coil 1 and the terminals 5.
Therefore, the decrease of a total height of the conventional transformer with respect to the circuit board is restricted, and the decrease of the thickness and size of the electronic equipment in which the conventional transformer is used is also restricted according to the total height of the conventional transformer.